(a bit late, but what the heck.)
For your first run, (just to make this a bit more generally useful) you'll probably spend a couple of days before ascending. The suggested target is about 10 Hero Souls, and around level 140. Most of those HS will come from hero levels, unless you get unusually lucky with Primal bosses. Check out an idle or active build guide to see suggestions on what to buy with those HS.
After that, most of the calculators that give a suggested level to ascend seem to recommend ascending when it takes you more than a couple of seconds per kill. This obviously is different for everyone, depending on their upgrades etc, but is a pretty good guideline to follow for "efficient" leveling.
Apply HS to level ancients as recommended by your preferred calculator. Google for "clicker heroes simple idle guide" for a basic rundown on how to get started until you're passing the 500's or so with ease. There's probably a similar document for active builds, too.
Once you've got your basic ancients chosen, it mostly becomes a bit "rinse and repeat". I break the short runs up with occasional deep runs, usually adding +50 or +100 to my highest zone... which so far gives me enough HS to buy a new ancient most of the time, and adds a bunch to the prize from Quick Ascension.
Speaking of QA.. for rubies...
The "double damage forever" buy is guaranteed worth it. 50 rubies isn't that much for a permanent boost (like an ancient, it lasts through your ascensions).
in general, the preferred/recommended buy is the Quick Ascension for 50 rubies.
Gilds are free from progression, and according to someone's math, you have to buy tons of them to make any real difference come late-game.
Gold is a waste since you just earn it all the time, and can't take it with you when you ascend. (it -can- help in early game, to buy your way past a wall, but usually it's better to just ascend.)
You get a random relic with every ascension, if you get high enough (it can spawn by default on any non-boss level over 99, up to 2/3 your highest ever zone). Further, since relics are almost entirely luck based, even spending thousands of rubies on them doesn't really guarantee anything.
Quick Ascension gives you a number of hero souls based on the highest zone you've ever completed. More HS makes you more powerful. This lets you advance to higher levels. This gives you more HS on each Quick Ascension. Essentially it's a profit-engine.